Voltage-regulator.



O. S. JOHNSON. VOLTAGE REGULATOR. APPLICATION FILED 00T.20.1904. RENEWEDNOV. 7, 1907.

961,41 1 Patented June 14,1910. fliW (2) 9&2.

76 ,4. C. 66/2 era for.

Afierzeraior:

[xc/ fer:

WITNESSE INVENTOR useful Improvements in Voltage-Regulators,

circuit of the alternating current generator;

UNITED STATES PATENT OFFICE.

CHARLES SUNDERLAND JOHNSON,

OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

VOLTAGE-REGULATOR.

961,411. Specification of Letters Patent Patented June 14, 1910.Application filed October 20, 1904, Serial No. 229,237. Renewed November7. 1907. Serial No. 401.163.

To all whom it may concern:

Be it known that I, CHARLES S. J OHNSON, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and l I and construction, not being an essentialpart of my invention, are not shown, except in the diagram, Figure 8.)It will be understood that, as is customary, the brushes ot' thecommutator-(Z on the converter are connected electrically with thebrushes on the commutator c of the direct current motor. The adjacentends of the two shafts carry the gears f and Z fixed thereon, as shown,and on one of them, as the shaft on of the direct current motor, Iloosely suspend an arm is which has a loosegear g, meshing with gearsand Z. The lower end of the arm It carries a contact piece it, which maytravel in either direction over the contact terminals of the rheostat j,which may be conveniently placed as shown in Figure 1.

Referring to Figure 3, which shows the of which the following is aspecification.

My invention relates to alternating current electric systems, andparticularly to means for automatic control of voltage regulatingapparatus in such systems. The primary object of the invention is toregulate and render practically constant the voltage or potential of analternating current circuit; and to provide improved automatic mechanismfor this purpose. Other objects and advantages gained will appear in thedescription hereafter. For purposes of illustration, I have shown hereinan arrangement of apsame apparatus in diagram, it will be seen paratusas applied to the case where an althat the rheostat coils y' are inseries with the ternating current generator provides current l fieldmagnet winding P of the alternating which, b means of a rotaryconverter, is current generator 0, and also with the deconverte intodirect circuit and a directsired eXciter Q, and therefore serving tocurrent motor is driven thereby. In the acregulate the current flowingin the field companying drawings, magnet winding of the alternatingcurrent generator by varying the resistance of its Figure 1 is a sideelevation of a converter and direct current motor mounted togethercircuit. on a frame and provided with my regulating From this apparatusit will now be clear apparatus, that if the voltage of the alternatingcurrent Figure 2 is an end elevation of the rheogenerator at O isvaried, the voltage of the stat and the traveling contact arm and meansfor shifting it, and

Figure 3 is a diagram of the same apparatus, illustrating the wiring ofthe various circuits, etc.

In practice I may em loy in my apparatus any devices which, by means ofvariations in the speed of the motor, will alter the voltage in thegenerator circuit, as by varying the resistance of the field magnetalternating current 'at the converter is altered in unison therewith,but the rotar converter, being a synchronous machine, will not bealtered in its speed of rotation unless the periodicity of the waves oralternations of potential in the alternating current generators at O isvaried. That is, the speed of the converter will not lie-changed byvariations in the voltage of the alternating current. Thus, supposingthe two gears f and l to be rotating in opposite directions at the samespeed, the position of the arm 70 will not change to shift the contactpiece N of the rheostat. But the direct current voltage delivered to themotor Z) will increase when the alternating current voltage isincreased, and will decrease when the latter is decreased, and therotative speed of the direct current motor will therefore fluctuate inunison with any fluctuations in the volt-age of the alternating currentgenerator driving it. In other words, the alternating current voltageand the direct current voltage generated by but, in the presentinstance, I have shown a difierential speed device which is gearedbetween the shafts of a converter and a direct current -motor. Thus, inthe accompanying Figure 1, it will be seen that upon a common base Ihave placed a rotary converter a and a direct current motor I), withtheir independent shafts in alinement with each other; It will beunderstood that the collector rings 0 of the converter are electricallyconnected to the armature of an alternating current generator (whoseposition OF CHICAGO, ILLINOIS, ASSIGNOR. BY MESNE AS- SIGNMENTS, TO THEWESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY.

the rotary converter a, and the rotative speed of the direct currentmotor 6 will fluctuate in unison, and the alternating current voltagewill directly vary the speed of the I illustrated its use, what I claimand desire I shaft of the direct current motor, and gear I l l l tosecure by patent, is the following 1. The combination with a generator,a rotary converter supplied with current therefrom, and a driven motorsupplied with Z; But when the alternating current voltage current fromthe rotary converter, of means of the generator 0 is increased, andtherecontrolled by the relative speeds of the mofore the rotativespeedof the direct current tor and converter for varying the voltage motor isincreased, the two gears f and Z will of the generator circuit. notrotate at the same speed, and, conse- 2. The combination with agenerator, a quently, the gear 6 will be driven around rotary convertersupplied with current and carry with it the arm 70 which will movetherefrom, and a motor supplied with curthe contact piece over thecontact terminals f rent from the rotary converter, of a rheostat of therheostat j in such a direction as to imin the field magnet circuit ofthe generator, pose a greater resistance in the circuit of the andautomatic means controlled by the relaexciter, and therefore reduce thestrength of i tivespeeds of rotation of the converter and the field ofthe alternating current generator F the motor for varying the activeresistance 0. This will result in decreasing the alterof the rheostat.nating current voltage and, consequently, 3. The combination with aenerator, a the speed of the direct current motor until rotary convertersupplied with current it attains the same speed as the rotarycontherefrom, and a motor supplied with ourverter, when the motion ofthe arm k will I rent from the rotary converter, of a rheostat cease,but not necessarily at its original poin the field magnet circuit of thegenerator, sition because it may be necessary to take a l and a systemof gears connected to the shafts new position to change the resistancein the of the converter and the motor, and mechanfield circuit, thuschanging the alternating 1 ism by which variations of the relativespeeds current voltage. That is, when the alternatof said two shaftswill vary the active reing current voltage is decreased, consesistanceofsaid rheostat. quently decreasing the rotative speed of the 4. Involtage control apparatus, the comgear Z, the relations between thespeeds of bination with a generator, a rotary converter the gears Z andf will be such as to drive the supplied with current therefrom, and adiarm is back in the other direction, moving rect current motor suppliedwith current the contact piece it so as to interpose less retherefrom,of a rheostat, concentrically sistance in the circuit of the fieldmagnet P mounted gear wheels driven respectively by of the alternatingcurrent generator, until a the shafts of the converter and the motor,

an idle gear engaging both of said gears and moving the contact arm ofthe rheostat, substantially as described.

5. In an automatic voltage control apparatus, the combination with agenerat r, a rotary converter supplied with current t eretwo shafts othe converter and motor; but from, and a motor supplied with current thegist of my invention is the provision of from the rotary converter, of arheostat in any means for varying the voltage of the althe field magnetcircuit of the enerator, a ternating current generator by reason ofvasystem of gears driven by the s afts of the riations 1n the s eed ofthe direct current or converter and the motor, and a differential othermotor with relation to the speed of the ear mechanism meshin with saidgears. and synchronous machine. Nor am I confined having means foralterm the active resistto the apparatus in which the variation of anceof the rheostat, su stantially as dethe resistance at the rheostatvaries the cur scribed. rent in the circuit of the field magnet of theIn testimony whereof, I have hereunder generator 0, as it is evidentthat such rheosigned my name in the presence of the two stzlilt may,with similar efi'efit,1be1placed in subscribing witnesses. ot ercircuits connected wit t 1e a ternatin T current circuit. The variousadvantages 0? CHARLES SUNDERLAND JOHLSON the apparatus will be apparentto those fal Witnesses:

PAUL CARPENTER,

miliar with the art.

Having thus described my invention and ALBERT C. HOWARD.

uation of this action, the alternating current voltage will be keptpractically constant.

It is to be understood that I do not limit myself to the differentialgear mechanism, depending u on the relative speeds of the balance of sed 1s reached. By the contin- I

